DNA is the recipe for life. DNA is a molecule found in the nucleus of every cell and is made up of 4 subunits represented by the letters A, T, G, and C. The order of these subunits in the DNA strand holds a code of information for the cell. Just like the English alphabet makes up words using 26 letters, the genetic language uses 4 letters to spell out the instructions for how to make the proteins an organism will need to grow and live.
Small segments of DNA are called genes. Each gene holds the instructions for how to produce a single protein. This can be compared to a recipe for making a food dish. A recipe is a set of instructions for making a single dish.
An organism may have thousands of genes. The set of all genes in an organism is called a genome. A genome can be compared to a cookbook of recipes that makes that organism what it is. Every cell of every living organism has a cookbook.